Anal fissure is a common painful condition affecting the anal canal.
Although, the majority of acute fissures heal spontaneously, some do not resolve and become chronic.
Chronic anal fissures are traditionally treated by anal dilation or lateral sphincterotomy.
However, these surgical treatments may cause incontinence in up to 30% of patients.
|Differences were found between the placebo, the 0.1% GTN and the 0.4% GTN.|
Recent trials have shown that nitric oxide donors, such as glyceryl trinitrate (GTN), can reduce sphincter pressure and heal up to 70% of chronic fissures.
In this study, published in the latest issue of Gut, researchers addressed the dose-response to 3 different concentrations of GTN ointment.
They compared these concentrations with placebo in a double blind randomized controlled trial.
They team assessed 0.1%, 0.2%, and 0.4% GTN ointment applied at a dose of 220 mg twice daily.
The primary end point was complete healing of the fissure.
The research team recruited 200 patients from 18 centers over an 8 month period.
The team found that after 8 weeks of treatment the healing rate in the placebo group was 38%, compared with 47% for 0.1%, 40% for 0.2%, and 54% for 0.4% GTN. These responses were not found to be significantly different.
The researchers performed a secondary analysis excluding fissures without secondary criteria for chronicity.
Healing rates were then found to be 24% in the placebo group, compared with 50% in the 0.1% GTN group, 36% in the 0.2% group, and 57% in the 0.4% GTN group.
The team found a statistically significantly difference between the placebo and the 0.1% GTN and 0.4% GTN. As well as for the GTN treated group as a whole.
Dr Scholefield's team concluded, "The results of this study have demonstrated the significant benefit of topical GTN when applied to patients suffering from chronic anal fissures but acute fissures showed a tendency to resolve spontaneously".
"The high proportion of fissures which healed in the placebo group suggests that the definition of ‘chronicity' needs to be reassessed".
"Further studies are required to confirm the optimal therapeutic strategy".